Method of reinforcing catalyst reaction

ABSTRACT

A method is provided for enhancing the catalytic reaction, by disposing a semiconductor catalyst in a fluid which includes charged particles and generating a magnetic field in the space where the semiconductor catalyst is disposed so as to impart electromagnetic induction energy to the charged particles. This method is capable of carrying out the reduction of nitrogen oxides, dechlorination of organic chlorine compounds and other reactions efficiently.

TECHNICAL FIELD

The present invention relates to a method of enhancing a catalyticreaction and, more particularly, to a technique for a magnetic fieldcatalyst process which utilizes magnetic field and charged particles toenhance catalytic reactions such as oxidation, reduction,denitrification, desulfurization and dechlorination by means of asemiconductor catalyst. This technology is useful for efficiently andeconomically processing chemical substances dissolved in gases or waterin a large scale through such reactions as oxidation and. reduction, andis applicable specifically to chemical plants, remedial operation forenvironmental pollution, water purification, deodorization, airpurification and agricultural/livestock farms.

BACKGROUND ART

A technology to activate or reform a fluid (gas or liquid) by applying amagnetic field to the gas or liquid has been known in the prior art. Atechnology is also widely known by which a semiconductor catalyst suchas titanium oxide is irradiated with ultraviolet radiation thereby tocause oxidation, reduction, denitrification, desulfurization anddechlorination between the catalyst surface and gas or liquid whichmakes contact with the surface (photocatalyst process).

However, the effect and reaction of these techniques, when appliedindividually, have been insufficient and can last for only a shortperiod of time.

In the case of the photocatalyst process, in particular, it is essentialto apply a sufficient amount of ultraviolet radiation to the catalystsurface for the catalytic reaction to take place. Large scalecommercialization of this technique has been hindered by such hurdles asvarious factors that hamper the efficient transmission of theultraviolet radiation energy to the catalyst surface (stain on thecatalyst surface, dispersion of light by fine particles, absorptionand/or attenuation of the light energy by liquid phase, etc.) and lowenergy efficiency (catalytic effect per unit radiation energy).

DISCLOSURE OF INVENTION

The present invention aims at combining the prior art technologies ofmagnetic activation of a fluid and optical catalyst process to overcomethe drawbacks of both technologies. Specifically, the present inventionprovides a method of enhancing the catalytic reaction of a semiconductorwhich is capable of making maximum use of the catalyst power of thesemiconductor and sustaining, the power, by utilizing theelectromagnetic induction energy imparted to charged particles whichmove in a magnetic field for the purpose of augmenting the catalyticreaction. Particularly it is intended to provide methods for reducingnitrogen oxides and dechlorinating organic chlorine compoundseffectively by applying the technology of the present invention.

The present invention, which solves the problems described above,provides a method of enhancing the catalytic reaction, which comprisesdisposing a semiconductor catalyst in a fluid which includes chargedparticles, generating a magnetic field in the space wherein thesemiconductor catalyst is disposed to impart electromagnetic inductionenergy to said charged particles, thereby enhancing the catalyticreaction of the semiconductor catalyst and a catalytic reactionapparatus comprising a semiconductor catalyst layer, a fluid supplyingand discharging means which introduces a fluid including chargedparticles to the catalyst layer and discharges the fluid, and a magneticfield generator which generates a magnetic field in the fluid.

According to the present invention, charged, particles are preferablyincluded in a fluid, which may be a gas or a liquid and makes contactwith a semiconductor catalyst, and a magnetic field is generated in thespace of the semiconductor catalyst where the fluid flows at apredetermined velocity, thereby imparting electromagnetic inductionenergy (Lorentz force) to the charged particles as shown in FIG. 4(a)and (b). The energy imparted to the charged particles is transferred tothe catalyst when the particles make contact therewith, therebyenhancing the catalyst power and causing various reactions (oxidation,reduction, denitrification, desulfurization and dechlorination) toproceed efficiently.

The same effect can be achieved not only by moving the charged particlesin the magnetic field but also by applying ultrasonic vibration to afluid contained in a vessel such as reactor thereby oscillating theparticles.

The semiconductor catalyst used in the present invention may be selectedin accordance to the intended catalytic reaction from among oxides suchas TiO₂ (titanium dioxide), ZnO, Nb₂O₅, SrTiO₃, PbNb₂O₆ and K₄Nb₆O₁₇,sulfides such as CdS and ZnS, and organic polymer such aspolyparaphenylene.

Among these, an dxide semiconductor is most preferably used and titaniumoxide which undergoes oxidizing and reducing reactions is specificallypreferable.

Charged particles carried by the, fluid may be the following substances.Nitrogen oxides, sulfur oxides, ozone and odor components, for example,may be used as the charged particles carried by the gas, For the chargedparticles carried by the liquid, nitrogen oxides; organic chlorinecompounds such as trichloroethylene, tetrachloroethylene,trichloroethane, dioxins and trihalomethane; Na and Mg ions; and variousartificial chemical substances may be used. Water molecules, which havepolarity and can be regarded as charged in a broader sense of the word,may also be used as the charged particles according to the presentinvention. A molecule having localized electron distribution may beregarded the charged particle according to the present invention. Thesecharged particles may not necessarily be subject to catalytic reaction.

The magnetic field used in the present invention may be either one-waymagnetic field (DC magnetic field) or alternating magnetic field.Catalyst power of the oxide semiconductor is,enhanced by alternating thedirection of the magnetic field at a high frequency. The magnetic fieldmay be generated by either electromagnets or permanent magnets, whichare arranged around or in a fluid path thereby to apply the magneticfield to the oxide semiconductor. The intensity of the magnetic field ispreferably not less than 0.1 Tesla (1000 Gauss).

Methods for imparting kinetic energy to the charged particles areclassified roughly into three types. The first is to cause the chargedparticles to undergo linear or circular movement unidirectionally (forexample, by means of fluid pressure). The second is to excite thecharged particles by ultrasonic or microwave energy so as to undergorandom motion. The third is to move the charged particles throughcollision with the catalyst and viscosity of the catalyst surface bymoving the semiconductor catalyst (for example, the semiconductorcatalyst is caused to undergo rotation, reciprocal or random motion inthe space occupied by the charged particles). The energy source formoving the charged particles may be (1) fluid pressure applied to thefluid, (2) various natural energy sources (potential energy, wind power,wave power, tidal wave energy, etc.), and (3) artificially generatedenergy (electric motor, internal combustion engine, ultrasound,microwave, etc.).

The semiconductor catalyst such as titanium dioxide ay be selected bygiving consideration to the following factors.

(1) Catalyst Size

The catalyst is preferably made of small particles with a large surfacearea, although a bulk catalyst such as a sheet or a block may also beused.

(2) A Compound Selected to Best Suit the Intended Catalytic Reaction.

It is known that a compound of titanium dioxide and lead has a higherefficiency of generating methane from CO₂ through photocatalyticreaction (carbon dioxide assimilation) about 30 times that of titaniumdioxide only, and it is possible to decompose water into hydrogen andoxygen by ultraviolet radiation energy. (decomposition of water) byhaving ruthenium carried by barium tetratitanate. Based on variousexperiences and technologies acquired on the optical catalyst processeswhich employ oxide semiconductors or the like, a suitable compound canbe selected for the intended catalytic reaction thereby to achieve theintended catalytic reaction more efficiently than in the prior art. Thisprocess may also be combined with the irradiation with light, as amatter of course.

(3) Combined Use of Other Catalysts

Catalyst power can be enhanced by combining activated carbon or ironoxide with the oxide semiconductors such as titanium dioxide.

(4) Combined Use of pH Control

Catalytic reaction of the present invention can be enhanced further byadding acid or alkali to the fluid so as to control the pH value to anoptimum level.

(5) Catalytic Reaction Can be Enhanced By Adding H₂O₂, Ozone or O⁻ ₃ tothe Fluid, Thereby Increasing the Free Radicals Generated.

In order to put the present invention into practical operation, acatalytic reaction apparatus is used which comprises a semiconductorcatalyst layer, a fluid supplying and discharging means that introducesa fluid including charged particles to the, catalyst layer anddischarges the fluid, and a magnetic field generator which generates amagnetic field in the fluid. While the semiconductor catalyst layer maybe disposed in a fluid passage or a tank such as a reaction vessel thecatalyst layer may be of any proper type such as fixed bed or fluidizedbed. There is also no limitation to the fluid supplying and dischargingmeans which may be, for example, a pump. While there is no limitation tothe magnetic field generator, one that is capable of applying analternating-magnetic field is preferable as described above.

The present invention, which is capable of enhancing the catalyst powerof the semiconductor and sustaining the power, can be applied to variousfields as follows.

1. Organic chemical synthesis and decomposition plants in general.

2. Preventive and remedial measures against environmental pollution

(1) Denitrification, desulfurization and dechlorination of exhaust gasdischarged from automobiles and waste incineration

(2) Denitrification, desulfurization and dechlorination of domesticwaste water, industrial waste water, water discharged from industrialwaste processing facility and water discharged from sewage treatmentfacility, removal and detoxification of various synthesized chemicalsubstances.

(3) Remedial measures against eutrophication of lake, river, pond andseawater (denitrification, desulfurization, etc.)

(4) Efficient removal of various synthesized chemical substances fromlake, river, pond and seawater and soil.

(5) A system to synthesize methane from carbon dioxide by means ofnatural energy, developed as countermeasure against global warming.

3. Health and sanitary applications

(1) Water purification (improving the water quality, removal anddetoxification of various artificial substances) in public water worksand privately owned purifying facilities (office building, hotel,hospital, home, etc.)

(2) Decomposition and/or removal of harmful substances (chlorine,trihalomethane, endocrine disrupters, etc.) included in potable watersupply.

(3) water purification for swimming pool and public bath.

(4) Air purifier which combines deodorizing and sterilizing functions

4. Application to industrial process

(1) Supply of purified water or magnetically activated water foragriculture (stock breeding, poultry farming, horticulture, etc.)

(2) Water purification system for fish tank

(3) Supplying hydrogen fuel for fuel cell by means of a waterdecomposition system utilizing natural energy

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows the structure of an apparatus for embodying the presentinvention without a magnetic field being applied according to Examples 1to 3,

FIG. 2 illustrates the arrangement of magnets and measuring points inthe apparatus according to Examples 1 to 3.

FIG. 3 schematically shows the principle of the present invention.

FIG. 4 explains the Lorentz force according to the present invention.

FIG. 5 shows Example 4 of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Examples of the present invention will be described below with referenceto accompanying drawings and data, but it should be noted that thepresent invention is not limited to the following Examples.

FIG. 1 shows the structure of the apparatus for embodying the presentinvention without a magnetic field being applied according to Examples 1to 3.

FIG. 2 illustrates the arrangement of the magnets and the measuringpoints in the apparatus according to Examples 1 to 3.

Examples 1 to 3 are examples of arranging neodymium magnets (Nd-Fe-Bmagnets) having surface magnetic flux density of 4,000 Gauss so as tosurround a fluid passage which is filled with a semiconductor catalystin the form of titanium dioxide particles, while a stock solution issent through the fluid passage under pressure to activate the stocksolution through oxidizing and reducing reactions of the titaniumdioxide, thereby purifying the stock solution.

In FIGS. 1 and 2, the reference numeral 1 denotes a passage for passingthe stock solution, 1 a denotes a stainless pipe which forms the fluidpassage and is 37 mm wide, 15 mm high and 1,000 mm long with wallthickness of 1.5 mm. The reference numeral 2 denotes titanium dioxidepellets which are an oxide semiconductor, 3 denotes a pump which forcesthe stock solution 4 to flow through the fluid passage at a low flowrate of 1.9 liters/min. or a high flow rate of 5.4 liters/min., 4denotes the stock solution to be processed, 5 denotes outflow of aliquid processed by activation, 6 denotes neodymium magnets havingsurface magnetic flux density of 4,000 Gauss, and 7 denotes several setsof induced electromotive force measuring probes placed at a distance of2.5 cm and opposite to each other. Measurements are taken at threepoints of A, B and C in the fluid passage 1. Point A is located at 25cmfrom the inlet of the fluid passage 1, point B is located at 40 cm fromthe inlet and point C is located at 75 cm from the inlet.(Electromagnetic induction energy)

Now the principle of generating the electromagnetic induction energy bythe magnetic field and the charged particles according to the presentinvention will be described below. A charged particle moving in amagnetic field receives a force called the Lorentz force. When thecharged particle enters a uniform magnetic field at right angles, theparticle receives the Lorentz force (electromagnetic induction energy)which is perpendicular to both the magnetic field and the movingdirection of the charged particle. The force F is given as the productof charge q of the charged particle, velocity v of the charged particleand the magnetic flux density B as follows.

F=qvB  (1)

Voltage generated across a pair of electrodes is given as:

et=es+(EL)=es+((V×B)L)  (2)

where es is an electrostatic potential, E is electric field vectorgenerated by a flow, L is the distance between the two electrodes placedin the magnetic field, V is the flow vector of the fluid and B is themagnetic field vector.

An energy gained by an electron through acceleration by a potentialdifference of 1V, denoted leV, is 1.6×10⁻¹⁹ j which can be convertedinto temperature by dividing with the Boltzmann constant k=1.38×10⁻²³JK⁻¹ as follows.

1eV=11,588.3 K=11,315° C.  (3)

The following description shows how much electromotive force will begenerated by the magnetic activation according to the present invention.The induced electromotive force was measured twice at each of the pointsA, B and C shown in FIGS. 1, 2 using tap water as the stock solutionwhile changing the flow velocity. Mean value of the measurements at eachpoint is shown in Table 1. Major charged particles included in the tapwater are Na⁺, Mg⁺⁺, Cl⁺ ions and the like.

TABLE 1-1 Without magnet induced electromotive force measured (unit: mV)Measuring Flow Low High Low speed - High speed - point velocity 0 speedspeed 0 velocity 0 velocity A −5.5 −6.5 −11.0 −1.0 −5.5 B 0.5 −3.0 −10.0−3.5 −10.5 C −7.5 −0.5 −2.0 7.0 5.5

TABLE 1-2 With magnets induced electromotive force measured (unit: mV)Measuring Flow Low High Low speed - High speed - point velocity 0 speedspeed 0 velocity 0 velocity A −10.0 −6.0 −8.0 4.0 2.0 B 189.0 149.5120.0 −39.5 −69.0 C −9.0 −3.5 6.0 5.5 15.0

From the results described above, the following findings were obtained.

1. Basic value of the electromotive force is varied significantly simplyby applying the magnetic field to the fluid passage 1. This issupposedly due to the electromotive force generated because thedistribution of the charged particles in the water is modified by thestrong magnetic field.

2. When water is forced to flow by the pump 3, the electromotive forcechanges significantly depending on the flow velocity. This is supposedlydue to the electromotive force generated by the electromagneticinduction energy (Lorentz force) because the kinetic energy istransferred to the charged particles existing in the magnetic field.

3. The electromagnetic energy generated at this time (value measured atpoint B in the table of the case provided with the magnets −69.0) istranslated to a temperature increase by the equation (3) as follows.

11,315° C.×69/1000=780.7° C.

(Catalyst for oxidizing and reducing reactions)

In the photocatalyst systems of the prior art which employs oxidesemiconductors such as titanium dioxide, it has been necessary to have asufficient intensity of optical energy directly reach the catalystsurface. In contrast, the present invention, which is based on the factthat the electromagnetic induction energy and the optical energy, thatis a kind of electromagnetic radiation, are essentially the same innature, makes it possible to effect photocatalytic reaction and chemicalreaction as a part of the electromagnetic induction energy, carried bythe charged particles, is transferred to the oxide semiconductors evenin a water solution or in a closed space which cannot be penetratedsufficiently by the light. This phenomenon may also be used incombination with optical energy of ultraviolet radiation, or the like.

EXAMPLE 1 Denitration Reaction Using Magnetic Field Catalyst

Denitration reaction is verified by measuring the concentrations ofnitrous acid and nitric ion in the processed liquid 5 after the magneticfield catalyst processing in cases A, B and C, using the apparatus shownin FIGS. 1, 2 and sodium nitrate solution as the stock solution 4.

1. Sodium nitrate solution having concentration of 10 mg/liter (10 ppm)(maximum permissible concentration for water quality of public waterworks) is prepared as the stock solution 4.

2. An experimental system similar to that of the test shown in Tables1-1 and 1-2 is used to measure the nitric acid ion concentration in theprocessed liquid after the magnetic field catalyst processing by meansof high performance liquid chromatography (HPLC), with the specimenbeing separated, caused to undergo grease reaction and finallyquantitatively determined by means of the intensity of color developedthrough a diazo reaction. In the following description, NOxconcentration is given in terms of the integration of voltage outputfrom a light absorbance detector (peak area).

Case A: Peak area of NOx detected from the solution prior to themagnetic field catalyst processing (stock solution 4) which includes 10ppm of sodium nitrate.

Case B: Peak area of NOx when processed in a system which is notprovided with magnets

Case C: Peak area of NOx in the case of magnetic field catalystprocessing provided with magnets.

The results are shown in Table 2.

TABLE 2 NO⁻ ₂ NO⁻ ₃ NO⁻ ₂₊₃ Residue concentration concentrationconcentration ratio mVs mVs mVs % Case A 0 5220 ± 81  5220 * Case B(without magnets) 511 ± 80 4550 ± 264 5061 97.0 Case C (with magnets) 68 ± 25 4117 ± 720 4180 80.1 n = 4

From the results described above, the following findings are obtained.

1. While about 10% of NO³¹ ³ was transformed into NO⁻², there was nochange observed in the total NOx in the case no magnets were installed.

2. When magnets were installed, about 20% of the total nitrogen oxideswas eliminated in a single run of the magnetic field catalystprocessing. This result clearly shows that activation by the magneticfield is necessary for the catalyst system of the present invention tofunction effectively.

3. Dramatic denitration effect can be expected by making this system ina multiple stage construction or circulating configuration.

EXAMPLE 2 Dechlorination By Means of Magnetic Field Catalyst

Pentachlorophenol (PCP) concentration in the processed water wasmeasured in cases D and E using the apparatus shown in FIGS. 1, 2 andthe PCP as the stock solution 4, and dechlorinating reaction wasverified.

1. PCP solution having concentration of 5 mg/liter (5 ppm) is preparedas the stock solution 4.

2. PCP concentration in the processed water 5 after the magnetic fieldcatalyst processing is measured using high performance liquidchromatography (HPLC) and an electrochemical instrument in an experimentsystem similar to that of the test described above.

Case D: Peak area of PCP detected from the solution prior to themagnetic field catalyst processing (,stock solution 4) which includes 5ppm of PCP.

Case E: Peak area of PCP detected from the solution which has beenprocessed by the magnetic catalyst system.

The results are shown in Table 3.

TABLE 3 PCP concentration mVs Residue ratio % Case D 20300 ± 260 * CaseE 15179 ± 647 74.8% n = 4

From the results described above the following findings are obtained.

1. About 25% of PCP was eliminated in a single run of the magnetic fieldcatalyst processing by applying the method of the present invention. Asit was verified, by a test paper method, that the residual chlorineconcentration in the solution which has been subjected to the magneticfield processing (processed liquid 5) showed a statistically significantincrease, it was assumed that the elimination of PCP was caused by thedechlorinating reaction.

2. Dramatic dechlorination effect can be expected by making this systempart of a multiple stage construction or circulating configuration.

3. PCP is a typical organic chlorine compound which has features commonto dioxins and PCB, and it is expected that other organic chlorinecompounds will also be dechlorinated.(neutralized) efficiently.

EXAMPLE 3 Enhancement of Magnetic Field Catalyst (Denitrating Reaction)

In the apparatus shown in FIGS. 1, 2, the fluid passage 1 is filled witha mixture of (1) titanium dioxide particles having diameter of 0.2 mm,(2) activated carbon particles having diameter of 0.2 mm and (3)magnetite particles having diameter of 5 mm which are mixed inproportion of 1:1:4 by volume. Similarly to Example 1, water includingnitric ion (stock solution 4) is forced to flow by the pump 3, and thechange in the nitric ion concentration is measured.

Results 1. Electromotive force at point B Without magnets Flow velocity:0 +5 mV Flow velocity: 1.7 L/min. −50 mV Difference in electromotiveforce −55 mV Provided with magnets Flow velocity: 0 +20 mV Flowvelocity: 1.7 L/min. −100 mV Difference in electromotive force −120 mVResult 2. Change in nitric ion concentration Solution includ- NO⁻ ₂ 1.3mVs ing 20 ppm of ion NO⁻ ₃ 11,603 mVs (Stock solution 4) (Residueratio) Solution after No magnets NO⁻ ₂ 1.1 mVs process (Processed NO⁻ ₃6,370 mVs solution 5) (59.4%) With magnets NO⁻ ₂ 1.5 mVs NO⁻ ₃ 4,010 mVs(34.6%)

From the results described above, the following findings are obtained.

1. Induced electromotive force energy is increased and the denitrationeffect becomes conspicuous by making the size of the titanium dioxideparticles smaller and adding the activated carbon and the magnetite.

2. This Example suggests the possibility of further enhancing theoxidizing and reducing reactions by combining a known method ofenhancing the photocatalytic reaction with the magnetic field catalystmethod of the present invention.

EXAMPLE 4 Magnetic Field Catalyst Assisted By Ultrasound

Experiment Procedure

1. Brown-colored glass cylinders 10 (100 ml capacity) were filled withstock solution 11, 80 ml of 5 ppm NO⁻³ solutions having different pHvalues (pH 3, 6, 9), as shown in FIG. 5. A catalyst 12 of the samematerial as that used in Example 3, comprising one gram of titaniumdioxide particles, one gram of activated carbon particles and five gramsof magnetite were. immersed in the solution. A neodymium magnet 13(4,000 Gauss) was attached to the bottom of the glass cylinder 10 fromthe outside.

2. Water tanks X, Y, Z provided with ultrasonic generators operating atvarious wavelengths and output power levels described below wereprepared. The glass cylinders 10 prepared in step 1 were immersed in thewater tanks X, Y, Z and ultrasound was generated for a predeterminedperiod of time, with the concentrations of nitrogen oxides beingmeasured before and after the application of the ultrasound. In FIG. 5,reference numeral 14 denotes an ultrasound generator, 15 denotes anultrasonic transducer installed at the bottom of the tank X, Y or Z.

Ultrasonic frequency Output power Energy Tank X 38 KHz 600 W 1 W/cm²Tank Y 150 KHz 1200 W 2.5 W/cm² Tank Z 770 KHz 2400 W 2.5 W/cm²

The following results were obtained.

Total NO⁻ ₂ NO⁻ ₃ NOx Duration concentration concentration concentrationTank X <pH 3> 0 min 1.3 mVs 2048 mVs 2049 mVs 10 min 32.3 mVs 1514 mVs1546 mVs 20 min 35.9 mVs 1383 mVs 1419 mVs <pH 6> 0 min 3.5 mVs 2727 mVs2730 mVs 10 min 43.7 mVs 1989 mVs 2032 mVs 20 min 47.9 mVs 1977 mVs 2025mVs <pH 9> 0 min 3.8 mVs 3413 mVs 3417 mVs 10 min 10.7 mVs 3230 mVs 3241mVs 20 min 13.9 mVs 3081 mVs 3095 mVs Tank Y <pH 3> 0 min 0.7 mVs 2384mVs 2385 mVs 10 min 418.7 mVs 1817 mVs 2236 mVs 20 min 689.1 mVs 1557mVs 2246 mVs <pH 6> 0 min 1.6 mVs 2046 mVs 2048 mVs 10 min 34.5 mVs 1870mVs 1905 mVs 20 min 268.9 mVs 1637 mVs 1906 mVs <pH 9> 0 min 2.0 mVs2877 mVs 2879 mVs 10 min 428.0 mVs 3277 mVs 3705 mVs 20 min 763.2 mVs3519 mVs 4282 mVs Tank Z <pH 3> 0 min 2.0 mVs 1728 mVs 1730 mVs 10 min1.2 mVs 2053 mVs 2054 mVs 20 min 2.7 mVs 1572 mVs 1575 mVs <pH 6> 0 min1.5 mVs 2874 mVs 2876 mVs 10 min 3.6 mVs 500 mVs 2504 mVs 20 min 2.8 mVs2133 mVs 2136 mVs <pH 9> 0 min 4.8 mVs 3141 mVs 3145 mVs 10 min 7.3 mVs3237 mVs 3244 mVs 20 min 7.4 mVs 3315 mVs 3322 mVs

From the results described above, the following findings were obtained.

1. The following tendencies were observed.

(1) The lower the pH value, the greater the effects of absorbing anddecomposing total nitrogen oxides. When evaluated in terms of totalnitrogen oxides dissolved in the solution, the denitration effect washighest at low frequency (38 kHz) followed by high frequency (770 kHz).

(2) At an intermediate frequency (150 kHz), no change was observed inthe total nitrogen oxides but an increase in the NO⁻ ₂ concentrationdependent on the imparted energy was observed in the solutions of pH 3and pH 6. In the solution of pH 9, the total nitrogen oxides showed anincrease. These results indicate that, at the intermediate frequency,not only the reactions of deriving NO⁻ ₂ from NO⁻ ₃ but also thereactions of deriving NO⁻ and NO⁻ ₂ from nitrogen and oxygen which aredissolved in the solution take place.

2. In the case of the magnetic field catalytic reaction assisted byultrasonic energy, denitrating reaction (reducing reaction) seems to bedominant in the low and high frequencies, while derivation of sulfateions (oxidizing reaction) from the dissolved gas is predominant at theintermediate frequency. This means that dominance of the oxidizingreaction or the reducing reaction varies depending on the magnetic fieldcatalyst conditions. Based on this fact, it is supposed that (1)ultrasonic vibration at a low or a high frequency is effective inremoving the nitrogen oxides from the aqueous solution and (2)ultrasonic vibration at intermediate frequency is effective in oxidizingand adsorbing nitrogen monoxide in the air.

3. It has been known from literature that water molecules decompose whenirradiated with ultrasound thus generating hydroxy radical “OH”(activated oxygen) and activated hydrogen “H·” (Makino et al., Radiat.Res., 96, 416-521, 1983). With the magnetic field catalyst method, it issupposed that the oxidizing and reducing reactions are carried out bythe efficient use of the hydroxy radical “OH·” (activated oxygen) andactivated hydrogen “H·” generated at this time.

Effects of the Invention

According to the present invention, as described above, electromagneticinduction energy can be imparted efficiently to all charged particles inthe fluid, and chemical reactions by means of the semiconductor catalyst(oxidation, reduction, denitrification, desulfurization anddechlorination) can be carried out efficiently by bringing the chargedparticles in the excited state into contact with the semiconductorcatalyst.

The magnetic field catalyst system of the present invention also has thefollowing advantages.

(1) The construction is very simple, and a large apparatus forindustrial application or a small apparatus for home use can be designedand manufactured relatively easily, provided that an apparatus (pump)for applying kinetic energy to the magnets and the fluid is available.

(2) Since the catalytic effect is utilized, the effect can be sustainedover an extended period of time, allowing easy maintenance and reducedcost.

The present invention also makes the following operations possible, thusmaking great contributions to the conservation of global environment andhuman welfare:

(1) Neutralization and removal of artificial chemical substances such asendocrine disruptors and detergents discharged into the naturalenvironment.

(2) Remedial measures to mitigate the effects of acid rain andeutrophication caused by waste water from farms and domestic wastewater.

(3) Dechlorination (neutralization) treatment of organic chlorinecompounds discharged in large quantity from waste processing facility orindustrial waste processing facility.

(4) Purification of potable water.

What is claimed is:
 1. A method of enhancing a catalytic reaction, whichcomprises disposing a semiconductor catalyst in a fluid which includescharged particles, and generating a magnetic field in the space whereinthe semiconductor catalyst is disposed to impart electromagneticinduction energy to said charged particles, thereby enhancing thecatalytic reaction of the semiconductor catalyst, wherein kinetic energyis imparted to the charged particles by means of ultrasonic energy inthe magnetic field.
 2. The method according to claim 1, wherein thekinetic energy is imparted to the fluid.
 3. The method according toclaim 1, wherein the space wherein semiconductor catalyst is disposed isa fluid passage or a tank.
 4. The method according to claim 1, whereinthe semiconductor catalyst is an oxide semiconductor catalyst.
 5. Themethod according to claim 4, wherein the oxide semiconductor catalystincludes titanium dioxide.
 6. The method according to claim 5, whereinthe titanium dioxide is used along with activated carbon and magnetite.7. The method as according to claim 1, wherein the magnetic field is analternating magnetic field.
 8. The method as according to claim 1,wherein the magnetic field has an intensity of at least 0.1 tesla. 9.The method according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein thecatalytic reaction is dechlorination of organic chlorine compoundsincluded in the fluid.
 10. The method according to claim 1 wherein thecatalytic reaction is reduction of nitrogen oxides included in thefluid.
 11. A method of enhancing a catalytic reaction, which comprisesdisposing a semiconductor catalyst in a fluid which includes chargedparticles, and generating a magnetic field in the space wherein thesemiconductor catalyst is disposed to impart electromagnetic inductionenergy to said charged particles, thereby enhancing the catalyticreaction of the semiconductor catalyst, wherein kinetic energy isimparted to the charged particles by means of microwave energy in themagnetic field.
 12. A catalytic reaction apparatus comprising: asemiconductor catalyst layer; a fluid supplying and discharging meanswhich introduces a fluid including charged particles to said catalystlayer and discharges the fluid; a magnetic field generator whichgenerates a magnetic field in the fluid; and an ultrasonic generator.13. A method of enhancing a catalytic reaction, which comprisesdisposing a semiconductor catalyst in a fluid which includes chargedparticles, and generating a magnetic field in the space wherein thesemiconductor catalyst is disposed to impart electromagnetic inductionenergy to said charged particles, thereby enhancing the catalyticreaction of the semiconductor catalyst, wherein the semiconductorcatalyst includes titanium dioxide, activated carbon, and magnetite.